Using Ethtool on Boot

Ethtool allows you to configure most network drivers with settings such as full or half duplex, speeds of 10 or 100, and auto negotiation. In order to have these settings take affect on boot, you need to add them to the boot process somewhere. There are various approaches for this, but if you use /etc/network/interfaces to configure your network (Debian, Ubuntu, etc), then this is the way to go: